Rapid Measurement and Identification Method for the Geometric Errors of CNC Machine Tools

Abstract

Error compensation technology offers a significant means for improving the geometric accuracy of CNC machine tools (MTs) as well as extending their service life. Measurement and identification are important prerequisites for error compensation. In this study, a measurement system, mainly composed of a self-developed micro-angle sensor and an L-shape standard piece, is proposed. Meanwhile, a stepwise identification method, based on an integrated error model, is established. In one measurement, four degrees-of-freedom errors, including two-dimensional displacement and two-dimensional angle of a linear guideway, can be obtained. Furthermore, in accordance with the stepwise identification method, the L-shape standard piece is placed in three different planes, so that the measurement and identification of all 21 geometric errors can be implemented. An experiment is carried out on a coordinate measuring machine (CMM) to verify the system. The residual error of the angle error, translation error and squareness error are 1.5″, 2 μm and 3.37″, respectively, and these are compared to the values detected by a Renishaw laser interferometer.

A Noncontact Method for Calibrating the Angle and Position of the Composite Module Array

“…Yang [11] introduced the measurement mechanism of using the angle sensor and the composite module to realize the four degrees of freedom information of the moving spindle, including the 2-D angle and 2-D displacement. Using this mechanism, the machine tool spindle drives the angle sensor to scan the composite module array.…”

“…Lv et al [10] proposed a 2-D displacement measurement method based on the rotating parabolic array, which extended the measurement range of the system in a discrete manner. Yang et al [11] formed freeform surfaces into an L-shaped array and established an error identification model to identify 21 geometric errors of the machine tool. Li et al [12] used an LED array and photoelectric detection sensor array to measure dust concentrations in different areas.…”

“…The composite module studied in this paper is composed of a plane and a rotating paraboloid. Yang and Lv have introduced the application of the composite module array in displacement measurement and 21 geometric errors of the machine tool detection, showing the broad prospect of the composite module array [10,11]. Owing to the existence of installation error, the relative angle and position of each composite module deviate from the theoretical value, which creates a huge error in the application of composite module arrays in measurement and other fields.…”

A Targetless Method for Simultaneously Measuring Three-Degree-of-Freedom Angular Motion Errors with Digital Speckle Pattern Interferometry

“…Computer numerical control (CNC) machine tools are the core production base of the equipment manufacturing industry, and there is an increasing demand for the tools’ precision requirements [ 1 , 2 , 3 , 4 , 5 ]. The precision detection of linear guide rails and rotary axes, which are the main precision motion units in the structure of CNC machine tools, is the key to precision machining and manufacturing [ 6 ]. Taking the linear guide rail as an example, its motion errors in three-dimensional (3D) space mainly consist of three linear errors along the axis directions (a positioning error in the direction of axis motion and two straightness errors perpendicular to the axis) and three angular errors of the motion around the axis (i.e., the pitch angle, yaw angle, and roll angle) [ 7 , 8 ].…”

Geometric Error Identification and Analysis of Rotary Axes on Five-Axis Machine Tool Based on Precision Balls

“…The geometrical error of machine tools is caused by imperfections of components and the imperfect assembly of parts, such as the straightness errors of the guideways, joint misalignments, angular offset and rotary axes separation errors [8,9]. The geometric error modeling of CNC machine tools 2 of 17 is based on the mathematical relationship between the geometric errors and machining errors of each component.…”